The biggest difference is that you play a lot of zone defense, which can be a huge problem for the playground-type, one-on-one maniacs.
Gist is doing OK, on a bad team in a weak regional tournament, with no Euroleague exposure.
He is third in scoring and second in rebounding on his own team. He has the tendency to be in foul trouble.
He leads the league in dunks, though; note that dunks are still worth 2 points in Europe.
Overall, there are at least 15/20 bigs that are better than him in the Italian league right now. Some of them are young.
To put things in perspective, a 23/24 years old Manu played for the best team, was undisputed MVP in a much more compe ive environment back then, with lots of very serious Eulogeague games played and won.
On the bright side, Gist can easily improve and his at ude seems to be quite right.